Part of living in a multicultural society is coexisting with people whose values are different from your own.
Yes, and we apparently need to decide how far we're willing to go with that.
If the motivation behind the refusal of service was because, according to Islam, women are bad or unclean or shouldn't be out in public or seeking haircuts, then, in Canada, that would be discrimination based on sex.
But the action wasn't about that. It was about a religious restriction against men. It's a restriction on men's behaviour, not women's. He is not restricting her right of freedom or her right to get a hair cut. He is simply saying he can't provide that service.
It's a Muslim-owned barber shop. Men don't cut women's hair there. That's a "sorry, we don't serve that here".